Cardiovascular disease is the leading killer of Americans today and heart attacks are its most visible sign. New medical discoveries now show that heart attacks are primarily caused by undetected vulnerable plaques. Intravascular Ultrasound (IVUS) imaging is a promising approach to the identification of vulnerable plaque, but current state-of-the-art transducers are unfocused and have narrow bandwidth, resulting in insufficient resolutions. The ultimate objective of the combined SBIR Phase I/ll program is the development of a focused ultrasonic microtransducer that can be mounted onto an IVUS catheter for identification of vulnerable plaque. The goal of the SBIR Phase I project is to develop a microelectronics-compatible process for the fabrication of miniature, focused polymer ultrasonic transducers and characterize their imaging performance. MEMS (microelectromechanical systems) technology will be used to prototype shaped polymer ultrasonic transducers. Standard ultrasonic testing tools and protocols will be used to characterize the transducer performance in saline.